抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Adipose tissue is a complex, essential, and highly active metabolic and endocrine organ. Besides adipocytes, adipose tissue contains connective tissue matrix, nerve tissue, stromovascular cells, and immune cells. Together these components function as an integrated unit. Adipose tissue not only responds to afferent signals from traditional hormone systems and the central nervous system but also expresses and secretes factors with important endocrine functions. These factors include leptin, other cytokines, adiponectin, complement components, plasminogen activator inhibitor-1, proteins of the renin-angiotensin system, and resistin. Adipose tissue is also a major site for metabolism of sex steroids and glucocorticoids. The important endocrine function of adipose tissue is emphasized by the adverse metabolic consequences of both adipose tissue excess and deficiency. A better understanding of the endocrine function of adipose tissue will likely lead to more rational therapy for these increasingly prevalent disorders. This review presents an overview of the endocrine functions of adipose tissue.

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Adipose Tissue as an Endocrine Organ

This critical review provides a processing-structure-property perspective on recent advances in cellulose nanoparticles and composites produced from them. It summarizes cellulose nanoparticles in terms of particle morphology, crystal structure, and properties. Also described are the self-assembly and rheological properties of cellulose nanoparticle suspensions. The methodology of composite processing and resulting properties are fully covered, with an emphasis on neat and high fraction cellulose composites. Additionally, advances in predictive modeling from molecular dynamic simulations of crystalline cellulose to the continuum modeling of composites made with such particles are reviewed (392 references).

/pdf/cellulose-nanomaterials-review-structure-properties-and-2z8x922p3v.pdf

Cellulose nanomaterials review: structure, properties and nanocomposites

Obesity is a principal causative factor in the development of metabolic syndrome. Here we report that increased oxidative stress in accumulated fat is an important pathogenic mechanism of obesity-associated metabolic syndrome. Fat accumulation correlated with systemic oxidative stress in humans and mice. Production of ROS increased selectively in adipose tissue of obese mice, accompanied by augmented expression of NADPH oxidase and decreased expression of antioxidative enzymes. In cultured adipocytes, elevated levels of fatty acids increased oxidative stress via NADPH oxidase activation, and oxidative stress caused dysregulated production of adipocytokines (fat-derived hormones), including adiponectin, plasminogen activator inhibitor-1, IL-6, and monocyte chemotactic protein-1. Finally, in obese mice, treatment with NADPH oxidase inhibitor reduced ROS production in adipose tissue, attenuated the dysregulation of adipocytokines, and improved diabetes, hyperlipidemia, and hepatic steatosis. Collectively, our results suggest that increased oxidative stress in accumulated fat is an early instigator of metabolic syndrome and that the redox state in adipose tissue is a potentially useful therapeutic target for obesity-associated metabolic syndrome.

/pdf/increased-oxidative-stress-in-obesity-and-its-impact-on-2ocfpcn6dr.pdf

Increased oxidative stress in obesity and its impact on metabolic syndrome

Lipid homeostasis in vertebrate cells is regulated by a family of membrane-bound transcription factors designated sterol regulatory element–binding proteins (SREBPs). SREBPs directly activate the expression of more than 30 genes dedicated to the synthesis and uptake of cholesterol, fatty acids, triglycerides, and phospholipids, as well as the NADPH cofactor required to synthesize these molecules (1–4). In the liver, three SREBPs regulate the production of lipids for export into the plasma as lipoproteins and into the bile as micelles. The complex, interdigitated roles of these three SREBPs have been dissected through the study of ten different lines of gene-manipulated mice. These studies form the subject of this review.

/pdf/srebps-activators-of-the-complete-program-of-cholesterol-and-1sop601qwq.pdf

SREBPs: activators of the complete program of cholesterol and fatty acid synthesis in the liver

Co-trimoxazole (trimethoprim-sulfamethoxazole) and pyrimethamine-sulfadoxine have been recommended for treatment and prophylaxis, respectively, of Pneumocystis carinii pneumonia (PCP) However, toxic epidermal necrolysis (TEN) occurred in three of four patients with acquired immunodeficiency syndrome (AIDS) during the course of treatment or prophylaxis of PCP with these agents On the other hand, 14 patients with PCP treated with pentamidine never developed TEN Because the incidence of adverse skin reactions is higher among patients with AIDS than those without AIDS, and TEN is a severe, potentially fatal skin reaction, sulfonamide-containing drugs should be given cautiously to patients with AIDS

Three cases of acquired immunodeficiency syndrome complicated with toxic epidermal necrolysis.

Hepatitis G virus in the liver and serum of patients with hepatocellular carcinoma

Post-transcriptional RNA editing modulates gene expression in a condition-dependent fashion. We recently discovered C-to-Ψ editing in Vibrio cholerae tRNA. Here, we characterize the biogenesis, regulation, and functions of this previously undescribed RNA editing process. We show that an enzyme, TrcP, mediates the editing of C-to-U followed by the conversion of U to Ψ, consecutively. AlphaFold-2 predicts that TrcP consists of two globular domains (cytidine deaminase and pseudouridylase) and a long helical domain. The latter domain tethers tRNA substrates during both the C-to-U editing and pseudouridylation, likely enabling a substrate channeling mechanism for efficient catalysis all the way to the terminal product. C-to-Ψ editing both requires and suppresses other modifications, creating an interdependent network of modifications in the tRNA anticodon loop that facilitates coupling of tRNA modification states to iron availability. Our findings provide mechanistic insights into an RNA editing process that likely promotes environmental adaptation. 

/pdf/sequential-action-of-a-trna-base-editor-in-conversion-of-2v9sy2ce.pdf

Sequential action of a tRNA base editor in conversion of cytidine to pseudouridine

In this study, enzymatic synthesis was conducted using cellodextrin phosphorylase (CDP), sucrose phosphorylase (SP), and sucrose with 1-azido-1-deoxy-β-glucoside (β-glucosyl azide) as the acceptor in phosphate buffer at pH 7.0. This yielded cellulose oligomers (degree of polymerization, DP ≈ 10) with azido groups at the reducing end as a white precipitate. A suspension of cellulose microcrystals with exposed azido groups on the surface was obtained via dissolution and recrystallization of the synthetic products dispersed in water by heating. The flat, ribbon-like cellulose microcrystals were a crystalline form of cellulose II and were several micrometers in length and several hundred nanometers in width. The microcrystals were 5.1–5.2 nm thick, which is equivalent to the chain length of cellulose oligomers with DP ≈ 10. When the cellulose II microcrystal suspensions were dried under a horizontal static magnetic field of 8 T, oriented films were obtained, wherein the microcrystals were aligned three-dimensionally. Synchrotron X-ray diffraction studies of the films revealed that the easy and intermediate axes (χ1 and χ2, respectively) of the cellulose II crystals corresponded approximately to the [1 1 0] and [1 $$\overline{1 }$$
 0] directions, respectively.

Satoshi Kimura

Papers

Three cases of acquired immunodeficiency syndrome complicated with toxic epidermal necrolysis.

Hepatitis G virus in the liver and serum of patients with hepatocellular carcinoma

Sequential action of a tRNA base editor in conversion of cytidine to pseudouridine

Three-dimensional alignment of cellulose II microcrystals under a strong magnetic field

Synthesis and characterization of α-1,3-alt-α-1,4-glucan (nigeran) ester derivatives